Method
- Mapper
- PT
- Ansatz
- UCC
- Optimizer
- COBYLA
- Maximum iterations
- 40
- Best energy (Ha)
- -5.06698
O2
BeyondH2 hardware VQE and fixed-parameter remeasurement · hardware · ibm_pittsburgh
Final energy-4.9849918478hartree
Shots1024
Runtime executionsingle-job
Resilience0
MappingPT
Active space4e4o
Parity mapping with full symmetry tapering · Shots and precision · Resilience settings
Execution
- Mode
- hardware
- Provider
- IBM Quantum
- Compute resource
- ibm_pittsburgh
- Resource type
- quantum processor
- Processor family
- Heron
- Processor model
- ibm_pittsburgh
- Processor revision
- 3
- Qubits
- 156
- Connectivity
- Not recorded
- Runtime execution
- single-job
- Shots
- 1024
- Precision
- 0.03125
- Resilience
- 0
- Submitted
- 2026-08-15T22:13:21+00:00
- Wall time (s)
- 28844.8
Molecular system
- Charge
- 0
- Multiplicity
- 3
- Basis
- sto3g
- Active space
- 4e4o
- Active electrons
- 4
- Spatial orbitals
- 4
- Active orbital indices
- Not recorded
- Geometry units
- angstrom
Circuit
- Logical qubits
- 4
- Physical qubits
- 4
- Parameters
- 1
- Depth
- 74
- Two-qubit gates
- 12
- Hamiltonian terms
- 50
Scientific provenance
- Cohort
- primary heron
- Reference method
- CASCI
- Reference energy (Ha)
- -5.362649434129489
- Energy convention
- Qiskit Nature active-space qubit Hamiltonian; nuclear and inactive-space constants excluded
- Absolute error (Ha)
- 0.377658
- Signed error (Ha)
- 0.377658
- Total QPU time (s)
- 114
- Calibration time
- 2026-08-15T21:45:58+00:00
- Mean readout error
- 0.008544921875
- Mean two-qubit gate error
- 0.003694187315005981
Software
- Qiskit
- 1.4.3
- Qiskit Aer
- 0.17.1
- Qiskit Algorithms
- 0.3.1
- Qiskit Ibm Runtime
- 0.40.1
- Qiskit Nature
- 0.7.2
Molecular geometry (angstrom)
| Atom | x | y | z |
|---|---|---|---|
| O | 0 | 0 | 0 |
| O | 0 | 0 | 1.216 |
Dataset publication
Associated articles
- The winner's curse in hardware VQE: drift-differenced remeasurement of finite-shot selection bias DOI 10.48550/arXiv.2609.27704 arXiv 2609.27704 published preprint
Compute access
- Fraunhofer Quantum Now and EQeS · IBM Quantum · allocation: Fraunhofer Quantum Now
Optimization trajectory
19 recorded objective evaluations. Charts use cumulative time so convergence cost remains comparable across calculations.
Download trajectory CSV · Download trajectory JSON
| Attempt | Outcome | Energy (Ha) | Elapsed (s) | Quantum (s) | Parameters |
|---|---|---|---|---|---|
| 1 | succeeded | -5.0599088832 | 2068.47 | 6 | [0.0] |
| 2 | succeeded | -4.2360492827 | 1702.7 | 6 | [1.0] |
| 3 | succeeded | -4.1037941047 | 2251.99 | 6 | [-0.9999999999999999] |
| 4 | succeeded | -4.6962145639 | 1703.46 | 6 | [0.5] |
| 5 | succeeded | -4.9054741446 | 2859.72 | 6 | [-0.25000000000000006] |
| 6 | succeeded | -4.8160900207 | 1157.79 | 6 | [0.1] |
| 7 | succeeded | -4.9176264076 | 1277.51 | 6 | [-0.1] |
| 8 | succeeded | -5.0348863775 | 1034.78 | 6 | [0.049999999999999996] |
| 9 | succeeded | -4.7566372549 | 1581.58 | 6 | [-0.024999999999999998] |
| 10 | succeeded | -5.0669827141 | 487.628 | 6 | [0.010000000000000004] |
| 11 | succeeded | -5.0363575491 | 1581.73 | 6 | [0.020000000000000007] |
| 12 | succeeded | -4.7967424843 | 2062.46 | 6 | [0.005000000000000003] |
| 13 | succeeded | -5.0520235329 | 971.919 | 6 | [0.012500000000000004] |
| 14 | succeeded | -5.0258378111 | 1424.52 | 6 | [0.009000000000000005] |
| 15 | succeeded | -5.0567641911 | 364.751 | 6 | [0.011000000000000003] |
| 16 | succeeded | -5.0269463124 | 1669.07 | 6 | [0.009500000000000003] |
| 17 | succeeded | -4.8982510725 | 879.586 | 6 | [0.010250000000000004] |
| 18 | succeeded | -5.0413794577 | 879.451 | 6 | [0.009900000000000004] |
| 19 | succeeded | -4.9849918478 | 2879.59 | 6 | [0.010100000000000003] |
Independent fixed-parameter remeasurements
These measurements reevaluate saved parameter vectors without running the optimizer. They are kept separate from the optimization trajectory.
| Vector | Epoch | Shots | Resilience | Measurements | Mean energy (Ha) | Minimum (Ha) | Maximum (Ha) | Allocated QPU time (s) |
|---|---|---|---|---|---|---|---|---|
| theta_best | EPOCH-2B4918A2E64142FB | 1024 | 0 | 7 | -5.0578576202 | -5.1054547754 | -4.9887404927 | 28 |
| theta_best | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -5.0526751289 | -5.0602646521 | -5.0405928614 | 12 |
| theta_best | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -5.0875613080 | -5.1072305252 | -5.0694686301 | 38.4 |
| theta_best | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.9904413830 | -5.0509861166 | -4.9199296962 | 15.9 |
| theta_best | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.2977087173 | -5.3163440751 | -5.2828227052 | 41.7 |
| theta_final | EPOCH-2B4918A2E64142FB | 1024 | 0 | 7 | -5.0406671226 | -5.0961921191 | -4.9953824815 | 28 |
| theta_final | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -5.0694416825 | -5.1011701595 | -5.0422687837 | 12 |
| theta_final | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -5.0944279615 | -5.1185869898 | -5.0660106127 | 38.4 |
| theta_final | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.9961501176 | -5.0294525175 | -4.9334540704 | 15.9 |
| theta_final | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.2898002418 | -5.3010433618 | -5.2813037895 | 41.7 |
Means below combine the displayed measurements descriptively. Inspect epochs and replicates in the download before drawing statistical conclusions.